Understanding the relevant physical mechanisms in jet noise generation has long been a topic of great interest in the fluids community, with the goal of developing quieter engines. Starting with [1]}, attention has been given to large-scale coherent structures in these flows and their connection with the far-field sound. [2]} identified these structures, using smoke visualisations, which revealed trains of “puffs” with a clear amplitude modulation, comprising regions of growth, saturation and decay. These wavepacket structures have been shown to be responsible for most of the downstream acoustic radiation in turbulent jets [3]}, [4]}, [5]}.
